Abstract: The body lightweight design is of great significance to the energy saving and emission reduction of vehicles. In order to reduce the weight of a certain sport utility vehicle (SUV) model in the late stage of development, the agent model technology is applied to build the body in white optimization process. Firstly, the finite element model of SUV body in white is established, and the torsional stiffness performance is simulated and analyzed as the constraint condition of optimization design. Through two sensitivity analyses, 66 key components and 38 design variables are screened. Based on Isight optimization platform, the design of experiments is carried out and a angent model aiming at the body mass is constructed. The HYBRID algorithm is used to optimize the thickness of key components. After optimization, the torsional stiffness of the body in white is basically unchanged, and the body mass is reduced. This optimization process has a good effect on body in white weight reduction in the late stage of vehicle development.

Key words: Body in white; Lightweight; Finite element analysis; Agent model; Size optimization

摘要： 车身轻量化设计对汽车的节能减排有重要意义，为了对处于开发后期的某运动型多用 途车（SUV）车型进行减重优化，应用代理模型技术搭建白车身优化流程。首先建立 SUV 白 车身有限元模型，对扭转刚度性能进行仿真分析并作为优化设计的约束条件，通过两次灵敏 度分析，筛选出 66 个关键部件，38 个设计变量，基于 Isight 优化平台，进行试验设计并构建 了代理模型，以车身质量为目标，采用 HYBRID 算法对关键部件的厚度进行尺寸优化设计。 优化后的白车身扭转刚度基本保持不变，车身质量得到降低。此优化流程在车型开发后期的 白车身减重方面具有良好效果。

关键词: 白车身；轻量化；有限元分析；代理模型；尺寸优化